Apple founder Steve Jobs has resigned as chief executive of the software giant and will be replaced by its chief operating officer Tim Cook.

Mr Jobs, who underwent a liver transplant following pancreatic cancer, said he could no longer meet his chief executive's duties and expectations.

The Silicon Valley legend will become chairman of the firm.

The 55-year-old has been on medical leave for an undisclosed condition since 17 January.

In a short letter to the board of Apple, Mr Jobs wrote: "I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's chief executive, I would be the first to let you know.

"Unfortunately, that day has come. I hereby resign as chief executive of Apple.

"I believe Apple's brightest and most innovative days are ahead of it. And I look forward to watching and contributing to its success in a new role.

"I have made some of the best friends of my life at Apple, and I thank you all for the many years of being able to work alongside you."

Apple board member Art Levinson paid tribute to Mr Job's contribution to the company: "Steve's extraordinary vision and leadership saved Apple and guided it to its position the world's most innovative and valuable technology company."'Hugely successful'

Analysts said the move was not unexpected, and would have little impact on the day-to-day running of the company.

"Steve is [still] going to be able to provide the input he would do as a chief executive," said Colin Gillis at BGC Financial.

"But Tim has been de facto chief executive for some time and the company has been hugely successful. The vision and the roadmap is intact."

Mr Jobs is widely seen as the creative force that has driven Apple to become one of the world's biggest companies.

Thanks to innovative and hugely popular products such as the iPod, the iPhone and more recently the iPad, Apple has become one of the most sought after brands in the world.

No, what's sad is AIDS is still an issue in 1st world countries and is completely controllable. Cancer is excusable because there isn't any 1 catalyst. We know exactly where you get AIDS, and we can easily test to see if you've got it.

Anyway, back on topic... Steve Jobs was and is an ásshole... but because he was an ásshole he stuck to his guns and enforced his vision, which luckily it was a pretty good vision. He did very good things for Apple and really helped revolutionize the mobile industry. We may have eventually made it on our way with mp3 players and smartphones, but the rapid adoption of the iPod and the iPhone really pushed people to start demanding more from their devices and made a lot of other OEMs wake up.

I just hope Steve led a personal life that was satisfying and he's still able to enjoy his time here.

Founding father of the Wiibrew Packgen.
About 2 noob posts away from going ape sh*t

Apple will continue to operate and I'd be surprised if it doesn't operate better than whenever Steve was there. Steve overrode many important ideas and decisions and those have ultimately hurt the company. I'm hoping someone less selfish steps in.